Methods for manufacturing polishing pad and polishing apparatus

ABSTRACT

The present invention relates to a method for manufacturing a polishing pad. The method of the invention includes the steps of (a) providing a releasing carrier; (b) providing a foaming resin composition; (c) coating the foaming resin composition of the step (b) on the carrier of the step (a); and (d) curing the foaming resin composition of the step (c). The invention also provides a process for manufacturing a polishing apparatus.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method for manufacturing a polishingpad and a process for manufacturing a polishing apparatus.

2. Description of the Related Art

Polishing generally refers to a wear control for a preliminary coarsesurface in a process of chemical mechanical polishing (CMP), which makesthe slurry containing fine particles evenly dispersed on the uppersurface of a polishing pad, and at the same time places a substrateagainst the polishing pad and then rubs the substrate repeatedly with aregular motion. The substrate may be objects such as a semiconductor, astorage medium substrate, an integrated circuit, an LCD flat-panelglass, an optical glass and a photoelectric panel. During the polishingprocess, a polishing pad must be used for polishing the substrate, andthe quality of the polishing pad directly influences the polishingeffect of the substrate.

FIG. 1 shows a schematic view of a polishing apparatus with aconventional polishing pad. The polishing apparatus 1 includes a lowerbase plate 11, a mounting sheet 12, a substrate 13, an upper base plate14, a polishing pad 15 and slurry 16. The lower base plate 11 ispositioned opposite to the upper base plate 14. The mounting sheet 12 isadhered to the lower base plate 11 through an adhesive layer (not shown)and is used for carrying and mounting the substrate 13. The polishingpad 15 is mounted on the upper base plate 14, and faces to the lowerbase plate 11 for polishing the substrate 13.

The operation mode of the polishing apparatus 1 is as follows. First,the substrate 13 is mounted on the mounting sheet 12, and then both theupper and lower base plates 14 and 11 are rotated and the lower baseplate 11 is simultaneously moved downward, such that the polishing pad15 contacts the surface of the substrate 13, and a polishing operationfor the substrate 13 may be performed by continuously supplementing theslurry 16 and using the effect of the polishing pad 15.

A conventional method for manufacturing the polishing pad is asdisclosed by U.S. Patent No. 2006/0035573, which comprises foaming apolymer resin solution by infiltrating air, adding a bridging agent, andthen filling the solution into an appropriate mold. After forming acolumnar elastomer by high temperature or chemical crosslinking curinginteraction, and removing the mold, then, the polishing pad is formed bycooling and cutting into slices. In the conventional method formanufacturing the polishing pad, when foaming the polymer resin solutionby infiltrating air, the air easily floats due to its low density. As areason, the air is not easy to uniformly distribute as filling thesolution into the mold. The air content of an upper part of the columnarelastomer is too much, and the air content of a lower part of thecolumnar elastomer is too less, so only a middle part of the columnarelastomer can be used. Furthermore, if an interior region of thecolumnar elastomer exists a defect such as unevenly foaming; severalpolishing pads positioned in the interior region are all affected.Moreover, it is difficult to control the process of mold filling,especially when the filling size rises. For example, the prolongedfilling time may affect the curing of the resin and thereby affect thepost processing. When applying the conventional polishing pad in thechemically mechanical polishing method, the flatness of the substrate ispoor due to the poor quality of the polishing pad, and the rise of theuneven degree of the substrate causes polishing particles in the slurrybe remained on a surface of the substrate and scrap the surface of thesubstrate to be polished. For example, in a wafer manufacture, ascraping of a wafer surface affects stability and affects a postmanufactures of lithography, development, and etching. After microintegrated circuit multiple overlaid, the stability is also reducedwhich increases the defective rate, and further increases the cost.

SUMMARY OF THE INVENTION

The invention adopts a coating method for manufacturing a polishing pad,and a polishing pad of uniformly foaming is obtained thereby, andthickness of the polishing pad is controlled easily. A post processing,storage and transportation are improved also and the polishing pad canbe applied in a continuously manufacture.

The invention provides a method for manufacturing a polishing padcomprising:

-   -   (a) providing a carrier, wherein the carrier is a releasing        material;    -   (b) providing a foaming resin composition;    -   (c) coating the foaming resin composition of the step (b) on the        carrier of the step (a); and    -   (d) curing the foaming resin composition of the step (c).

The invention also provides a process for manufacturing a polishingapparatus, wherein the polishing apparatus comprising:

-   -   a base plate;    -   a substrate;    -   a polishing pad, which is adhered on the base plate for        polishing the substrate; and    -   a slurry, which is contacting with the substrate for polishing;    -   wherein the process comprises the aforementioned method for        manufacturing the polishing pad.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic view of a polishing apparatus with aconventional polishing pad;

FIG. 2 shows a schematic view of a polishing apparatus with a polishingpad according to the invention;

FIG. 3 shows a view under the scanning electron microscope of thepolishing pad according to the invention; and

FIG. 4 shows a view under the scanning electron microscope of theconventional polishing pad.

DETAILED DESCRIPTION OF THE INVENTION

The invention provides a method for manufacturing a polishing padcomprising:

-   -   (a) providing a carrier, wherein the carrier is a releasing        material;    -   (b) providing a foaming resin composition;    -   (c) coating the foaming resin composition of the step (b) on the        carrier of the step (a); and    -   (d) curing the foaming resin composition of the step (c).

The term “carrier” as used herein refers to an element which allows thefoaming resin composition formed thereon and the foaming resincomposition can be easily removed after curing. Preferably, the carrieris a sheet; in another aspect, the carrier is a releasing material. Theterm “releasing material” as used herein refers to a material which doesnot react with the foaming resin composition in the polishing padmanufacturing process and the foaming resin composition can be easilyremoved after the curing. Preferably, the releasing material is “a filmwith low permeability.” The term “film with low permeability” as usedherein refers to a film or thin film that substantially prevents thefoaming resin composition on an upper surface of the film with lowpermeability according to the invention from permeating to a lowersurface of the film with low permeability. In one preferred embodimentof the invention, the film with low permeability can be formed on a basematerial, for example, a paper. Preferably, the carrier comprises apolyethylene glycol terephthalate film, a polypropylene film, apolycarbonate film, a polyethylene film, a polyethylene terephthalatefilm, a releasing paper or a releasing fabric. Additionally, thepreferable polypropylene is oriented polypropylene.

Preferably, the carrier is continuously provided, for example, is arolling releasing material. The rolling releasing material can be usedby roll to roll. Comparing to the conventional manufacture relative tomolding or casting a single polishing pad, the method according to theinvention improves batch uniformity.

In one embodiment of the invention, the foaming resin compositioncomprises a resin, a foaming agent, and a bridging agent.

The resin according to the invention is, preferably, an elastomer. Asused herein, the term “elastomer,” also known as “elastic polymer,”refers to a type of polymer that exhibits rubber-like qualities. Whenpolishing, the elastomer serves as a good buffer to avoid scraping asurface of the substrate to be polished. As used herein, the term“foaming resin” refers to a material containing a thermoplastic resinand a thermodecomposing foaming agent. Preferably, the resin comprisesat least one selected from the group consisting of polyurethane,polyolefin, polycarbonate, polyvinyl alcohol, nylon, elastic rubber,polystyrene, poly aromatic molecules, fluorine-containing polymer,polyimide, crosslinked polyurethane, crosslinked polyolefin, polyether,polyester, polyacrylate, elastic polyethylene, polytetrafluoroethene,poly (ethylene terephthalate), poly aromatic amide, polyarylalkene,polymethyl methacrylate, a copolymer thereof, a block copolymer thereof,a mixture thereof, and a blend thereof.

The term “foaming agent” as used herein refers to a resin foaming agentor method according the invention. A manner of foaming the resinaccording the invention can be chemically foaming or physically foaming,wherein the chemically foaming manner uses an agent to carry on achemical reaction to yield gas for being evenly distributed in the resincomposition. Besides, the physically foaming manner comprisesinfiltrating gas into the resin composition for being evenly distributedin the resin composition by stiffing.

The term “crosslinked agent” as used herein refers to an agent that maygenerate a crosslinked reaction with the resin according to theinvention and cure the resin under an appropriate condition. The kind ofthe crosslinked agent is determined according to the kind of the resin.

In one preferred embodiment of the invention, the foaming resincomposition further comprises a polishing particle. The polishingparticle can coordinate with the slurry for polishing. The polishingparticle is evenly distributed in the foaming resin composition;wherein, it can exist in the resin of the polishing pad, and it can alsoexist in foaming pores of the polishing pad. Preferably, the polishingparticle comprises cerium dioxide, silicon dioxide, aluminum oxide,yttrium oxide, or ferric oxide. Additionally, the particle diameter ofthe polishing particle is from 0.01 μm to 10 μm.

In one embodiment of the invention, the step (c) comprises bladecoating, printing wheel coating, roll extrusion coating or spraying. Themanner of coating may be chosen by artisans skilled in this field.Besides, the preferred coating is continuously coating.

The method according the invention, the step (d) is curing the foamingresin composition of the step (c). The manner of curing may be chosen byartisans skilled in this field according to the kind of the curing resinand bridging agent needed. In one preferred embodiment of the invention,the curing step is curing the foaming resin composition which has beendried at a high temperature of 60° C. to 130° C.

In one preferred embodiment of the invention, the method furthercomprises a surface finishing step, which is finishing a surface of thecured resin composition in the step (d). The embodiment of finishing ispolishing or shaving a part of the surface. The manner of polishing orshaving the part of the surface may be chosen by artisans skilled inthis field, for example, using sandpaper to polish or a knife to shave;wherein the manners of the polishing or shaving are well known toartisans skilled in this field.

In one preferred embodiment of the invention, the method furthercomprises a step of groove forming, which is forming at least one grooveon the surface of the cured resin composition in the step (d). Themanner of processing of forming the groove on the surface of the curedresin composition may be chosen by artisans skilled in this fieldaccording to the specification, for example, using laser processing. Thegroove helps the slurry flow in the polishing, and preferably, the ratioof the groove range and the groove wide is from about 1 to about 0.05.

In one preferred embodiment of the invention, the method according tothe invention is to collocate with a continuously provided carrier. Thesteps of the invention are coordinated as a production line with theusing of a roller, and providing, coating, curing, finishing, and grooveforming, can be performed continuously and the manufacture is moreeasily.

In one preferred embodiment of the invention, the method furthercomprises a step (e) of removing the carrier. Preferably, the step ofremoving the carrier is removing the polishing pad from manufacturingequipment after the manufacture method is completed. On the other hand,the step of removing the carrier is removing the carrier from thepolishing pad when polishing. The specific manner of the removingdepends on the carrier, for example, the manner is peeling.

In one embodiment of the invention, the method further comprises a stepof applying an adhesive on the surface of the cured resin compositionwhich makes the polishing pad fix on the base plate. The adhesive may bechosen by artisans skilled in this field according to the specification.

In one embodiment of the invention, the method further comprises a stepof applying an adhesive on a surface of the carrier which makes thepolishing pad fix on the base plate. The adhesive may be chosen byartisans skilled in this field according to the specification.

In one preferred embodiment of the invention, the adhesive is a pressuresensitive adhesion or polyurethane. The term “pressure sensitiveadhesion” as used herein refers to a thin carrier film of and anadhesive agent on the upper and lower side of the thin carrier film.Preferably, the thin carrier film is selected from the group consistingof polyethylene terephthalate, polypropylene and polyethylene.

Because the invention adopts a coating method for manufacturing thepolishing pad, the step of mold filing is avoided, and a polishing padof uniformly foaming is obtained. Furthermore, it is easy to control thethickness of coating. It benefits the post processing, storage andtransportation. It can be applied in the continuously manufacture andreduce the manufacturing costs because of eliminating the steps ofprocess.

The invention also provides a process for manufacturing a polishingapparatus, wherein the polishing apparatus comprising:

-   -   a base plate;    -   a substrate;    -   a polishing pad, which is adhered on the base plate for        polishing the substrate; and    -   a slurry, which is contacting with the substrate for polishing;    -   wherein the process comprises the aforementioned method for        manufacturing the polishing pad.    -   Preferably, the polishing apparatus further comprises:    -   a lower base plate positioned opposite to the base plate; and    -   a mounting sheet adhered to the lower base plate for mounting        and securing the substrate.

FIG. 2 shows a schematic view of a polishing apparatus with a polishingpad according to the invention. The polishing apparatus 2 includes alower base plate 21, a mounting sheet 22, a substrate 23, an upper baseplate 24, a polishing pad 25 and slurry 26. The lower base plate 21 ispositioned opposite to the upper base plate 24. The mounting sheet 22 isadhered to the lower base plate 21 through an adhesive layer (not shown)and is used for carrying and mounting the substrate 23. The polishingpad 25 is mounted on the upper base plate 24 and faces to lower baseplate 21 for polishing the substrate 23.

The operation mode of the polishing apparatus 2 is as follows. First,the substrate 23 is mounted on the mounting sheet 22, and then both theupper and lower base plates 24 and 21 are rotated and the upper baseplate 24 is simultaneously moved downward, such that the polishing pad25 contacts the surface of the substrate 23, and a polishing operationfor the substrate 23 may be performed by continuously supplementing theslurry 26 and using the effect of the polishing pad 25.

The following Examples are given for the purpose of illustration onlyand are not intended to limit the scope of the present invention.

Example

A resin composition is stirred uniformly and air is infiltrated into theresin composition at a rate of 1000 rpm to 4000 rpm. Then, the resincomposition is coated on a releasing paper with a scraper. The resincomposition is cured at 110° C. for 1 minute, and then dried at 80° C.for 30 seconds in an oven, and the surface is shaved. FIG. 3 shows aview under the scanning electron microscope, and the figure shows thatthe foam is evenly distributed.

Comparative Example

A resin composition is stirred uniformly and air is infiltrated into theresin composition at a rate of 1000 rpm to 4000 rpm, then the resincomposition is filled into a mold. The resin composition is heated at60° C. for 3 minutes and removed from the mold. The resin composition isfurther heated at 110° C. for 16 seconds, and cut into slices. FIG. 4shows a view under the scanning electron microscope. Because the resincomposition is foamed by infiltrating air, the air easily floats due toits low density. The foam is difficult to be uniformly distributed asfilling the composition into the mold. The air content of an upper partof the resin composition is too much, and the air content of a lowerpart of the resin composition is too less, so only a middle part of theresin composition can be used.

The physically evaluation results of the aforementioned polishing padsare as shown in the following Table 1, which shows that the polishingpads obtained in Examples have the lower compression rate and the higherhardness, and the polishing pads obtained in Examples are better thanthe polishing pads obtained in Comparative Examples. Furthermore, theamount of transformation is also relatively lower.

TABLE 1 Hard- Com- Coating Film ness Com- pression Den- intervalthickness (shore pression recover sity (mm) (mm) D) rate rate (g/cm³)Example 0.75 0.50-0.55 16-18 1.58% 89.77% 0.75 Comparative 2.502.90-3.10 14-16 5.16% 73.46% 0.63 Example

While embodiments of the present invention have been illustrated anddescribed, various modifications and improvements can be made by personsskilled in the art. The embodiments of the present invention aretherefore described in an illustrative but not restrictive sense. It isintended that the present invention is not limited to the particularforms as illustrated, and that all the modifications not departing fromthe spirit and scope of the present invention are within the scope asdefined in the appended claims.

What is claimed is:
 1. A method for manufacturing a polishing padcomprising: (a) providing a carrier, wherein the carrier is a releasingmaterial; (b) providing a foaming resin composition; (c) coating thefoaming resin composition of the step (b) on the carrier of the step(a); and (d) curing the foaming resin composition of the step (c). 2.The method according to claim 1, wherein the carrier comprises apolyethylene glycol terephthalate film, a polypropylene film, apolycarbonate film, a polyethylene film, a polyethylene terephthalatefilm, a releasing paper or a releasing fabric.
 3. The method accordingto claim 1, wherein the carrier is continuously provided.
 4. The methodaccording to claim 1, wherein the foaming resin composition comprises aresin, a foaming agent, and a bridging agent.
 5. The method according toclaim 4, wherein the resin comprises at least one selected from thegroup consisting of polyurethane, polyolefin, polycarbonate, polyvinylalcohol, nylon, elastic rubber, polystyrene, poly aromatic molecules,fluorine-containing polymer, polyimide, crosslinked polyurethane,crosslinked polyolefin, polyether, polyester, polyacrylate, elasticpolyethylene, polytetrafluoroethene, poly (ethylene terephthalate), polyaromatic amide, polyarylalkene, polymethyl methacrylate, a copolymerthereof, a block copolymer thereof, a mixture thereof, and a blendthereof.
 6. The method according to claim 1, wherein the foaming resincomposition further comprises a polishing particle.
 7. The methodaccording to claim 1, wherein the step (c) comprises blade coating,printing wheel coating, roll extrusion coating or spraying.
 8. Themethod according to claim 1, further comprising a surface finishingstep, which is finishing a surface of the cured resin composition in thestep (d).
 9. The method according to claim 1, further comprising agroove forming step, which is forming at least one groove on a surfaceof the cured resin composition in the step (d).
 10. The method accordingto claim 1, further comprising a step (e) of removing the carrier. 11.The method according to claim 1, further comprising a step of applyingan adhesive on a surface of the cured resin composition.
 12. The methodaccording to claim 1, further comprising a step of applying an adhesiveon a surface of the carrier.
 13. A process for manufacturing a polishingapparatus, wherein the polishing apparatus comprising: a base plate; asubstrate; a polishing pad, which is adhered on the base plate forpolishing the substrate; and a slurry, which is contacting with thesubstrate for polishing; wherein the process comprises the method formanufacturing the polishing pad according to claim
 1. 14. The processaccording to claim 13, wherein the carrier comprises a polyethyleneglycol terephthalate film, a polypropylene film, a polycarbonate film, apolyethylene film, a polyethylene terephthalate film, a releasing paperor a releasing fabric.
 15. The process according to claim 13, whereinthe carrier is continuously provided.
 16. The process according to claim13, wherein the foaming resin composition comprises a resin, a foamingagent, and a bridging agent.
 17. The process according to claim 16,wherein the resin comprises at least one selected from the groupconsisting of polyurethane, polyolefin, polycarbonate, polyvinylalcohol, nylon, elastic rubber, polystyrene, poly aromatic molecules,fluorine-containing polymer, polyimide, crosslinked polyurethane,crosslinked polyolefin, polyether, polyester, polyacrylate, elasticpolyethylene, polytetrafluoroethene, poly (ethylene terephthalate), polyaromatic amide, polyarylalkene, polymethyl methacrylate, a copolymerthereof, a block copolymer thereof, a mixture thereof, and a blendthereof.
 18. The process according to claim 13, wherein the foamingresin composition further comprises a polishing particle.
 19. Theprocess according to claim 13, wherein the step (c) comprises bladecoating, printing wheel coating, roll extrusion coating or spraying. 20.The process according to claim 13, further comprising a surfacefinishing step, which is finishing a surface of the cured resincomposition in the step (d).
 21. The process according to claim 13,further comprising a groove forming step, which is forming at least onegroove on a surface of the cured resin composition in the step (d). 22.The process according to claim 13, further comprising a step (e) ofremoving the carrier.
 23. The process according to claim 13, furthercomprising a step of applying an adhesive on a surface of the curedresin composition.
 24. The process according to claim 13, furthercomprising a step of applying an adhesive on a surface of the carrier.